Fuel injection system



Nov. 1, 1960 T. M. BALL 2,958,319

FUEL INJECTION SYSTEM Filed Sept. 5, 1959 2 Sheets-Sheet 1 w *1 NINVENTOR.

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Nov. 1, 1960 T. M. BALL FUEL INJECTION SYSTEM 2 Sheets-Sheet 2 FiledSept. 3, 1959 FUEL INJECTION SYSTEM Thomas M. Ball, Bloomfield Hills,Micln, assignor to Chrysler Corporation, Highland Park, Mich, acorporation of Delaware Filed Sept. 3, 1959, Ser. No. 837,902

Claims. (Cl. 123--119) This invention relates to a fuel injection systemparticularly suited for use in an automotive internal combustion engine.

In a type of fuel injection system with which the present invention isparticularly adapted pressurized fuel from a fuel pump is supplied by afuel feed conduit to the engine through fuel metering means operable inresponse to variations in engine speed and load. The fuel metering meansincludes a housing partitioned by a movable wall into a first fuelpressure chamber and a second or fuel pressure balancing chamber. Thefirst chamber comprises part of the feed conduit and has an orificetherein associated with valve means adjustable to vary the orifice andthereby to control the fuel flow to the engine. The movable wall isoperably connected with the valve means and with a sensor deviceresponsive to an engine operating condition and is shiftable to adjustthe valve means in accordance with the balance of forces effected by thesensor device and the pressure differential between the two chambers.

A pressure equalizing duct in communication with the pressure balancingchamber and the feed conduit at a location downstream of the meteringmeans maintains the same pressure differential between the first chamberand said downstream location that exists across the movable Wall. In theevent of sudden opening of the engine throttle for the purpose ofincreasing the fuel supply to the engine with such a system, a suddenoutflow of fuel from the first chamber results in a momentary change inthe forces on the movable wall causing the latter to move in a directionto decrease the volume of the first chamber and to increase the volumeof the second chamber. In consequence, without provision to thecontrary, fuel is robbed from the feed conduit via the equalizing ductin order to fill the increased volume of the second chamber. This causesmomentary leanness of the fuelair mixture during acceleration.

An object of the present invention is to provide simple and highlyefficient improved means for preventing such an occurrence and inparticular to provide means comprising a shiftable pressure actuatedvalve seat for said orifice cooperable with a valve element on saidmovable wall to vary the orifice, the valve seat being operablyconnected with the engine manifold pressure to be shifted thereby duringacceleration to augment said valve element in supplying additional fuelto the engine.

Other objects of this invention will appear in the following descriptionand appended claims, reference being had to the accompanying drawingsforming a part of this specification wherein like reference charactersdesignate corresponding parts in the several views.

Figure 1 is a fragmentary schematic sectional view of a fuel injectionsystem embodying the present invention.

Figure 2 is an enlarged fragmentary view of the valve and shiftablevalve seat within the dotted outline of Figure 1.

Figure 3 is a view similar to Figure 1, showing a modified form of theinvention.

2,958,319 Patented Nov. 1, 1960 Figure 4 is an enlarged fragmentary viewof the valve and shiftable valve seat within the dotted outline ofFigure 3.

It is to be understood that the invention is not limited in itsapplication to the details of construction and arrangement of partsillustrated in the accompanying drawings, since the invention is capableof other embodiments and of being practiced or carried out in variousways. Also it is to be understood that the phraseology or terminologyemployed herein is for the purpose of description and not of limitation.

Referring to Figure l, a fuel injection system is shown comprisingseparate cylinder banks 14 air intake manifold conduits 11, exhaustconduits 12, and exhaust manifolds 13. The system comprises a fuelsupply tank 14, an engine operated speed sensor 15, an engine loadsensor 16, an accelerator pump 17, and fuel injection nozzles 18. Thespeed sensor is provided with four housing portions separated from eachother by diaphragms 23, 24, and 25 to provide four chambers 26, 27, 28,and 29. Chamber 26 communicates with fuel tank 14 through conduit 30 andby means of fuel pump 31 submerged in tank 14 is supplied with fuel inadequate volume and pressure to exceed the maximum requirements of theengine regardless of the engine load or speed. A tubular return flowmetering orifice member 32 as described below connects chamber 26 with areturn flow conduit 33 which extends to fuel tank 14 to return excessfuel thereto. A shiftable rod 19 having at one end a flattened returnvalve element 35 registering with the upstream side of orifice or valveseat member 32 is secured to each of the diaphragms 23, 24, and 25 bysuitable grommets 34.

A flyweight support 36 pivotally supports flyweights 37 at 38 and issecured to a flexible shaft 39 operatively connected to the engine torotate at a speed directly proportional to engine speed. The flyweights37 have projections 20 which abut an end portion of rod 19 when theflyweights pivot outwardly in response to rotation of shaft 39, therebyto urge valve element 35 toward the orifice or seat member 32 againstthe opposite force of the fuel pressure in chamber 26 applied todiaphragm 23. As engine speed increases or decreases respectively, valveelement 35 is moved toward or away from metering orifice member 32 torestrict or increase the latters effective opening.

Although the present invention is illustrated herein by Way of examplewith a return flow type fuel injection system, it Will be apparent fromthe following that the invention has application with other than returnflow systems, as for example wherein orifice member 32 is closed andvalve 35 is applied to conduit 30 to restrict the fuel flow therethroughwith increasing pressure in chamber 26; or wherein conduit 30 is closedand the fuel is pumped in a reverse direction through conduit 33 intochamber 26, and valve 35 is applied to restrict orifice member 32 withincreasing pressure in chamber 26.

Chamber 26 is connected with a downstream chamber 40 via load meteringorifice 41 and thence with a downstream fuel distribution chamber orrosette 42 via fuel supply conduits 43 and 44 in series. A load meteringneedle 45 extends through orifice 41 and terminates in a reverselytapered end portion 46 registering with the upstream side of orifice 41.Needle 45 is operatively connected to a piston 47 reciprocable incylinder 48, which in turn is connected with a low pressure portion ofeach intake manifold 11 of said engine by conduit 49. Low

pressure transmitted through conduit 49 causes piston 4'7 to moveupwardly against the force of spring 50 and to urge the tapered valve 46into closer proximity with the sides of orifice 41 to progressivelyrestrict the latter. Conversely, with increasing pressure in the intakemanifolds, as for example with increasing load, spring 50 urges piston46 downwardly to increase the opening of orifice 411. Vent duct 4% inthe lower portion of cylinder 48 maintains the space below piston 47 atatmospheric pressure.

A separate nozzle feed conduit 51 extends from chamber 42 to each of thefuel injection nozzles 18 located downstream of the throttle valve 52 inthe air intake manifold 53. Chamber 40 is also connected to chamber 27of the speed sensor unit by a pressure equalizing conduit 54 to providean adjustment of the fuel pressure differential across the meteringorifice 41, as explained below.

An idle boost conduit 55 communicates with manifold 53 at a pointadjacent the edge of throttle valve 52 and with the chamber 23 of thespeed sensor unit in order to augment operation of the flyweights 37urging rightward movement of valve element 35 when the engine isoperated at low'speed and light load. By virtue of duct 55, the pressurein chamber 28 during such conditions is lower than in chamber 29 whichis vented to the atmosphere by vent 56. The pressure in chamber 29 thusurges valve element 35 toward orifice member 32 to retard the flow ofreturn fuel therethrough and provide an emichment of the engine fuelsupply. During high speed or high load operation, the pressuredifferential across diaphragm 25 has no appreciable effect.

The accelerator pump 17 has an inlet duct 57 in communication withreturn fiow conduit 33 via ball check valve 58 and receives fuel intothe lower portion of cylinder 59 upon upward movement of the acceleratorpiston 69. In the present instance, piston 60 is connected in accordancewith customary practice with the personally operated accelerator linkage61. The latter is suitably connected with throttle valve 52 and normallymaintains piston 60 in an elevated position against the tension ofspring 62 when throttle valve 52 is closed. Upon opening of valve 52 byoperation of the throttle linkage, as for example during acceleration orincreasing engine load, linkage 61 releases piston 69 for downwardmovement. The compressed spring 62 then moves piston 60 downwardly in apumping stroke to discharge pressurized fuel from cylinder 59. Uponactuation of throttle linkage 61 to close valve 52, piston 60 is raisedin an intake stroke against the force of spring 62. Fuel is then drawninto the lower part of chamber 59 below piston 69 via duct 57. Bleedduct 63 connects cylinder 59 above piston 60 with return conduit 33 tofacilitate operation of piston 6tl'and to prevent entrapment of fuel inthe upper portion of cylinder 59.

The lower chamber 79 of a fiuid containing pressure regulator orpressure increasing valve housing 80 is connected by duct 81 with thereturn flow conduit 33, the housing 80 being partitioned by a flexiblediaphragm 82 to provide the aforesaid lower chamber 79 and an upperchamber 83. A needle valve element 84 secured to diaphragm 82 to movetherewith extends upwardly to register with a metering orifice 85 whichcommunicates with conduit 44 adjacent its juncture with conduit 43. Abiasing spring 86 under compression between the underside of diaphragm82 and a lower portion of housing 80 urges needle valve element 84upwardly to maintain a predetermined minimum differential between thefuel pressure in conduit 43 and the fuel pressure in the return flowconduit 33, as described below. i

As is apparent from Figure 1, the pressure in conduit 33 augments theforce of spring 86 urging diaphragm 82 and needle valve 84 upwardly inopposition to the pressure in feed conduit 43 urging diaphragm 82downwardly. Upward or downward movement respectively of valve element 84progressively restricts or opens orifice 35. In the event of a pressureincrease in conduit33 for any cause, as for example by inclination ofthe vehicle to raise fuel tank 14 with respect to metering orificemember 32, the pressure increase is transmitted to the under side ofdiaphragm 82 to increase the restriction of orifice when the pressure infeed conduit 44 drops below a predetermined minimum value, as forexample when the engine is operating at low load. The pressure in feedduct 43 is thereby increased to increase the pressure in chamber 27 viaconduit 54 and also to increase the pressure in chamber 83 via duct 87connected with feed conduit 43.

The increased pressure in chamber 27 urges diaphragm 23 to the rightbecause of its larger area with respect to the area of diaphragm 24,causing valve element 35 to increase the restriction of metering orifice32. The latter action reduces the pressure in return conduit 33 and alsoin chamber 79. The resulting reduced upward force on diaphragm 82,augmented by the increased pressure chamber 83, tends to restore theopening of orifice 85 to the extent predetermined by biasing spring 36.Accordingly, any tendency to increase the pressure in return conduit 33results in a corresponding tendency to increase the pressure in chambers26 and 40, so that the pressure differential between conduits 33 and 43will not drop below a predetermined minimum value determined by theforce of spring 86. This structure is particularly important duringlight engine loads when the pressure downstream of port 85 is a minimum.Valve 84 assures a comparatively high minimum pressure upstream of port85 and minimizes the tendency of fuel vapor formation during suchconditions in the metering system.

The operation of the speed sensor 15 and load sensor 16 will bedescribed in relation to a static engine op erating condition, that isconstant engine speed and load. Under static conditions, the forceexerted on valve element 35 by flyweights 37 equals the force exerted onvalve 35 by the fuel pressure differential across diaphragm 23, wherebyvalve 35 is positioned with respect to orifice or seat member 32 so asto maintain a pressure differential across orifice 41 determined byengine speed. In this static condition, the amount of fuel delivered tothe rosette 42 is constant and is equal to the amount of fuel deliveredto the system by the pump 31 less the amount of fuel being returned tothe fuel tank 14 through the return flow conduit 33.

As throttle valve 52 is moved to a more open position by operation ofthe engine accelerator including linkage 61, an increase in manifoldpressure is transmitted to the load sensor piston 47 through conduit 49,enabling spring 50 to move piston 47 downwardly and thereby to move theload metering valve 46 to a more open position with respect to themetering orifice 41. The pressure differential existing across orifice41 and therefore across.

diaphragm 23 consequently tends to decrease as more fuel is allowed toflow into chamber 40. To prevent such a condition and to maintain thepressure difierential acrossorifice 41 at a value where the flow of fueltherethrough will satisfy the increased engine load requirement, thefuel pressure in chamber 26 is increased by movement of the return flowmetering valve 35 closer to orifice member 32 in consequence of theincreased pressure in chamber 27 which communicates via duct 54 withchamber 40. Thus the return fuel flow in conduit 33 is decreased and thefuel flow to the engine via conduits 43 and 44 is increased. Similarlywhen the engine speed is increased, the flyweights 37 exert increasedforce on valve 35 urging the latter rightward to restrict orifice member32. The result is to decrease the return fuel flow in conduit 33 andincrease the flow to the engine via conduits 43 and 44. The converseoperation will of course occur in the event of a reduction in engineload or speed.

The pressurized fuel discharged from cylinder 59 upon spring urgeddownward movement of piston 60 during acceleration is directed throughconduit 89 to the upper chamber 90 of a fluid containing pressureoperated check valve housing 91 which is partitioned by afiexiblediaphragm 92 into the aforesaid upper chamber 90 and a lower chamber 93.A shiftable needle valve element 94 secured to diaphragm 92 to movetherewith has a tapered upper end registering with an accelerationorifice 95 to close the latter. Upon downward movement of valve element94, chamber 90 communicates with chamber 42 via port 95 and duct 44.Needle valve 94 is normally maintained in the closed position shown by abiasing coil spring 96 under compression between the underside ofdiaphragm 92 and a lower portion of the housing 91. Chamber 93 is incommunication with return flow conduit 33 via duct 97, whereby excesspressure buildup in chamber 93 is avoided and the return flow in conduit33 is employed to augment spring 96 in maintaining valve element 94 inthe closed position.

In accordance with the foregoing, when accelerator piston 60 isdepressed to discharge fuel from cylinder 59 during an acceleratingoperation, the fuel output of pump 17 is directed into chamber 90 toforce diaphragm 92 downwardly against the tension of spring 96, therebycausing valve element 94 to open orifice 95. Opening of the latterorifice admits the accelerating fuel into conduit 14 and thence intochamber 42 and to the engine via the various fuel supply conduits 51.

It is also to be noted that upon rapid opening of throttle valve 52during acceleration of the engine, the manifold pressure in conduit 49increases, enabling spring 50 to move valve 46 suddenly downwardly todecrease the restriction at orifice 41. Without provision to thecontrary, the pressure in chamber 26 would drop momentarily and causerightward movement of diaphragm 23 with a resulting drop in pressure inchamber 27. The momentary low pressure in chamber 27 would rob fuel fromchamber 40 via conduit 54 and reduce the fuel pressure in chamber 40.The fuel supply to the engine would thus be reduced at the very timethat acceleration was desired. Coughing or momentary stalling of theengine would result.

In order to prevent such an occurrence, a branch conduit 100 of conduit49 opens into a pressure chamber 101 formed at the right end of a cavity102 in a housing portion 103 of the speed sensor 15, Fig. 2. Chamber 101is defined in part by the rigid side walls of housing 103 and a flexiblediaphragm 104 which is secured around its periphery to said side wallsin fluid sealing engagement therewith so as to partition chamber 101from a second pressure chamber 105 at the left side of diaphragm 104.Chambers 101 and 105 are thus separated from each other by diaphragm 104except at a restricted bleed duct 106 formed in housing 103 andconnecting chambers 101 and 105.

Chamber 103 is defined peripherally by the side walls of housing 103 andis defined at its right and left ends respectively by diaphragms 104 and107. The periphery of the latter diaphragm is connected in fluid sealingengagement with housing 103 and separates chamber 105 from a lowpressure fuel chamber 108 comprising the left end of cavity 102 whichopens into the left end of return flow conduit 33.

Cavity 102' enlarges leftward at 109 to receive the radial enlargement110 of a tubular adaptor 111 having a threaded right end screwed snuglyinto the left end of cavity 102. An G-ring type seal 112 provides aperipheral fluid seal between the juxtaposed walls of the enlargedportions 109 and 110 adjacent the outer periphry of the latter.Similarly a sealing gasket 113 provides a fluid seal between thejuxtaposed walls of the enlargements and 13.0 around the outer peripheryof the threaded portion of adaptor 111.

As illustrated in Figure 2, the seat or orifice member 32 comprises ashort tubular element freely slidable axially in the bore of tubularadaptor 110 and opening at ducts 114 into the left chamber 108 of cavity102, which in turn opens into conduit 33 as aforesaid. An annularmovement limiting shoulder 115 of member 32 6 limits the lattersrightward movement. The outer periphery of an annular guide 116 issnugly pressed or screwed into the opening of enlargement 110 tocomprise an integral unit therewith and has its inner periphery in freesliding and guiding relation with the tubular orifice member 32. Thelatter is thus free for limited leftward movement from the positionshown in Figures 1 and 2. An extension 117 integral with seat member 32mechanically connects the same with diaphragms 104 and 107 to causeaxial shifting of member 32 upon pressure actuated movement of thediaphragms.

It is apparent that when throttle valve 52 is opened rapidly during anaccelerating operation, the resulting pressure rise in conduit 49 istransmitted through conduit to the right side of diaphragm 104, therebyto move the latter and the freely shiftable orifice member 32 leftwardtoward valve element 35, provided that the increased force at the rightside of diaphragm 104 exceeds the force at the left side of the smallerdiaphragm 107 resulting from the fuel pressure in chamber 108. Inconsequence, the bore of the orifice or valve seat member 32 isrestricted during the initial period of acceleration. The return fuelflow in conduit 33 is reduced with a consequent pressure rise in chamber26 tending to increase the pressure differential across orifice 41 andto give the engine a burst of accelerating fuel as desired duringacceleration. Thus the momentary effect of reducing the restriction atorifice 41 during acceleration is minimized. This action is supplementedby operation of accelerator pump 17 as described above, although withcertain engine constructions the accelerator pump 17 can be eliminatedentirely.

After the momentary burst of accelerating fuel is supplied as a resultof the rapid opening of throttle valve 52, the pressure in chamber 101at the right side of diaphragm 104 will leak through restricted bleedorifice 106 to chamber at the left side of diaphragm 104. The effect ofthe accelerating fuel boost will last for the short time intervalrequired for the pressure leakage through bleed duct 106 toapproximately equalize the pressures at opposite sides of diaphragm 104.Thereafter the fuel pressure in chamber 108 acting on diaphragm 107 willurge seat member 32 to its rightward position illustrated and the normaloperation of the fuel metering system will be restored. In consequenceof the fuel pressure in chamber 108 urging the seat member 32 rightward,minor pressure fluctuations in the induction conduit 53 and in ducts 49,100 will not disrupt the normal operation of the fuel metering system.

It is also to be noted that during deceleration of the engine andmovement of throttle valve 52 toward its closed position shown, thepressure downstream of valve 52 and in conduits 49, 100 is reduced so asto assure rightward movement of diaphragm 104 and seat member 32 to thelimit of movement permitted by stop 115. In consequence, a minimum fuelpressure in chambers 26 and 40 will result in accordance with normaloperation of the fuel metering system, so that fuel flow to the engineand unburned fuel in the engine exhaust system are minimized duringrapid deceleration.

Figures 3 and 4 illustrate a fuel metering system similar to that shownin Figures 1 and 2,. the fuel metering means and the structure andmounting of the seat or orifice member 32 in housing 103 being the sameas in Figures 1 and 2. Thus corresponding parts are numbered the same inall drawings. In Figures 3 and 4, bleed orifice 106 is omitted anddiaphragms 105 and 107 are replaced by a single diaphragm 120 securedaround its periphery in fluid sealing engagement with housing 103.Diaphragm 120 partitions cavity 102 into left and right chambers, theformer chamber being in communication with ducts 114 and 33 to establishreturn fuel flow via orifice member 32 as before, and the latter chamberbeing connected by duct 100 with duct 49.

A spring 121 under compression between the right side of diaphragm 120and a portion of housing 103 partially opposes the fuel pressure at theleft side of diaphragm 120 to assure a sensitive response to pressureincreases in the induction system 53 and at the right side of diaphragm120. Upon opening of throttle valve 52 during acceleration, theincreased pressure at the right side of diaphragm 120 enables spring 121to urge the diaphragm 120 and seat member 32 leftward, thereby torestrict the bore of member 32 and increase the pressure in chamber 26as described above in regard to Figures 1 and 2. In consequence, thetendency for cavitation in chambers 27 and 40 and momentary stalling ofthe engine during the initial accelerating period are avoided.

I claim:

1. In a fuel system for an internal combustion engine having an airinduction conduit, fuel conduit means for supplying said engine withfuel, fuel metering means for regulating the fuel flow in said conduitmeans to said engine including a port in said conduit means, anadjustable valve seat at said port, a shiftable valve element cooperablewith said seat to regulate the fuel flow through said port, meansresponsive to changes in the fuel pressure in said conduit means andbeing operatively connected with said valve element to shift the same,valve actuating means responsive to an operating condition of saidengine and being cooperable with said valve element for shifting thesame, and means responsive to pressure changes in said induction conduitfor adjusting said valve seat.

2. In a fuel system for an internal combustion engine having an airinduction conduit, fuel conduit means for supplying said engine withfuel, fuel metering means for regulating the fuel flow in said conduitmeans to said engine including a port in said conduit means, anadjustable valve seat at said port, a shiftable valve element cooperablewith said seat to regulate the fuel flow through said port, meansresponsive to changes in the fuel pressure in said conduit means andbeing operatively connected with said valve element to shift the same,valve actuating means responsive to an operating condition of saidengine and being cooperable with said valve element for shifting thesame, and means responsive to pressure changes in said induction conduitduring acceleration of said engine for adjusting said seat to augmentoperation of said metering means tending to increase the fuel flow tosaid engine.

3. In a fuel system for an internal combustion engine having an airinduction conduit and a throttle valve in said induction conduit, fuelconduit means for supplying said engine with fuel, fuel metering meansfor regulating the fuel flow in said conduit means to said engineincluding a port in said conduit means, an adjustable valve seat at saidport, a shiftable valve element cooperable with said seat to regulatethe fuel flow through said port, means responsive to changm in the fuelpressure in said conduit means and being operatively connected with saidvalve element to shift the same, valve actuating means responsive to anoperating condition of said engine and being cooperable with said valveelement for shifting the same, and means responsive to the pressureincrease in said induction conduit downstream of said throttle valveduring acceleration of said engine for adjusting said seat to augmentoperation of said metering means tending to increase the fuel flow tosaid engine.

4. In a fuel system for an internal combustion engine having an airinduction conduit, fuel conduit means for supplying said engine withfuel, fuel metering means for regulating the fuel flow in said conduitmeans to said engine including a port in said conduit means, anadjustable valve seat at said port, a shiftable valve element cooperablewith saidseat to regulate the fuel flow through said port, meansresponsive to changes in the fuel pressure insaid conduit means andbeing operatively con nected with said valve element to shift the same,valve actuating means responsive to an operating condition of 5. In afuel system for an internal combustion engine.

having an air induction conduit, fuel conduit means for supplying saidengine with fuel, fuel metering means for regulating the fuel flow insaid conduit means to said engine including a port in said conduitmeans, an adjustable valve seat at said port, a shiftable valve elementcooperable with said seat to regulate the fuel flow through said port,means responsive to changes in the fuel pressure in said conduit meansand being operatively connected with said valve element to shift thesame, valve actuating means responsive to an operating condition of saidengine and being cooperable with said valve element for shifting thesame, means responsive to pressure changes in said induction conduitduring acceleration of said engine for adjusting said seat to augmentoperation of said metering means tending to increase the fuel flow tosaid engine, said last named means comprising a pressure chamber, amovable wall partitioning said pressure chamber into two parts and beingoperably connected with said seat, said pressure chamber at one side ofsaid movable wall being in communication with said induction conduit andbeing responsive to pressure changes therein, and a bleed ductconnecting the parts of said pres? sure chamber at opposite sides ofsaid wall for gradually equalizing the pressure at said opposite sides.

6. In a fuel system for an internal combustion engine having an airinduction conduit, fuel conduit means for supplying said engine withfuel, fuel metering means for regulating the fuel flow in said conduitmeans to said engine including a port in said conduit means, anadjustable valve seat at said port, a shiftable valve element cooperablewith said seat to regulate the fuel flow through said port, valveactuating means responsive to an operating condition of said engine andbeing cooperable with said valve element for shifting the same, an

actuating pressure chamber, a first pressure actuated,

movable wall defining a portion of said actuating chamher, a secondpressure actuated movable wall partition: ing said actuating chamberinto two parts and being operably connected with said seat to shift thelatter, said first wall being operably connected with said second wallto shift the latter, means for limiting movement of said.

second wall in one direction, means for applying the pressure in saidconduit means at the low pressure side of said port to said firstmovable wall to urge said second wall to the limit of movement in saidone direction, a bleed orifice connecting the two parts of saidactuating chamber, and means for connecting the pressure of saidinduction conduit with one of said actuating chamber parts to shift saidsecond wall and adjust said seat to augment operation of said meteringmeans tending to increase the fuel flow to said engine duringacceleration.

7. In a fuel system for an internal combustion engine having an airinduction conduit and a throttle valve in said induction conduit, fuelconduit means for supplying said engine with fuel, fuel metering meansfor regulating the fuel flow in said conduit means to said engineincluding a port in said conduit means, an adjustable valve seat at saidport, a shiftable valve element cooperable with said seat to regulatethe fuel flow through said port, valrve actuating means responsive to anoperating conditionof said engine and being cooperable with said valveelementfor shifting the same, an actuating pressure chamber, a firstpressure actuated movable wall defining a portion, of said actuatingchamber, a second pressure actuated movable wall partitioning saidactuating chamber into two 9 parts and being operably connected withsaid seat to shift the latter, said first wall being operably connectedwith said second wall to shift the latter, means for limiting movementof said second wall in one direction, means for applying the pressure insaid conduit means at the low pressure side of said port to said firstmovable wall to urge said second wall to the limit of movement in saidone direction, a bleed orifice connecting the two parts of saidactuating chamber, and means for connecting the pressure of saidinduction conduit downstream of said throttle valve with one of saidactuating chamber parts to shift said second wall and adjust said seatto augment operation of said metering means tending to increase the fuelflow to said engine during acceleration.

8. In a fuel system for an internal combustion engine having an airinduction conduit and a throttle valve in said induction conduit, fuelconduit means for supplying said engine with fuel, fuel metering meansfor regulating the fuel flow in said conduit means to said engine, saidfuel metering means including a fuel chamber in said conduit meanshaving a port, an adjustable valve seat at said port, a shiftable valveelement cooperable with said seat to regulate the fuel flow through saidport, a movable partition separating said chamber into two parts withsaid port being in one thereof, said partition being shiftable inresponse to changes in the fuel pressure differential at its oppositesides and being operatively connected with said valve element to shiftthe same, an actuating pressure chamber, a first pressure actuatedmovable wall defining a portion of said actuating chamber, a secondpressure actuated movable wall partitioning said actuating chamber intotwo parts and being operably connected with said seat to shift thelatter, said first wall being operably connected with said second wallto shift the latter, means for limiting movement of said second wall inone direction, means for applying the pressure in said conduit means atthe low pressure side of said port to said first movable wall to urgesaid second Wall to the limit of movement in said one direction, a bleedorifice connecting the two parts of said actuating chamber, and meansfor connecting the pressure of said induction conduit downstream of saidthrottle valve with one of said actuating chamber parts to shift saidsecond wall and adjust said seat to augment operation of said meteringmeans tending to increase the fuel flow to said engine duringacceleration.

9. In a fuel system for an internal combustion engine having an airinduction conduit, fuel conduit means for supplying said engine withfuel, fuel metering means for regulating the fuel flow in said conduitmeans to said engine including a port in said conduit means, anadjustable valve seat at said port, a shiftable valve element cooperablewith said seat to regulate the fuel flow through said port, valveactuating means responsive to an operating condition of said engine andbeing cooperable with said valve element for shifting the same, a springyieldingly urging said seat to a predetermined position of adjustment,an actuating pressure chamber, a pressure actuated movable wall defininga portion of said actuating chamber and being operably connected withsaid seat to shift the same, means for applying the pressure of saidconduit means at the low pressure side of said port to one side of saidmovable wall urging the latter in opposition to said spring, and meansconnecting the other side of said wall with the pressure of saidinduction conduit to adjust said seat to augment operation of saidmetering means tending to increase the fuel flow to said engine duringacceleration.

10. In a fuel system for an internal combustion engine having an airinduction conduit, fuel conduit means for supplying said engine withfuel, fuel metering means for regulating the fuel flow in said conduitmeans to said engine, said fuel metering means including a fuel chamberin said conduit means having a port, an adjustable valve seat at saidport, a shiftable valve element cooperi0 able with said seat to regulatethe fuel flow through said port, a movable partition separating saidchamber into two parts with said port being in one thereof, saidpartition being shiftable in response to changes in the fuel pressuredifferential at its opposite sides and being operatively connected withsaid valve element to shift the same, valve actuating means responsiveto an operating condition of said engine and being cooperable with saidvalve element for shifting the same, a spring yieldingly,

urging said seat to a predetermined position of adjustment, an actuatingpressure chamber, a pressure actuated movable wall defining a portion ofsaid actuating chamber and being operably connected with said seat toshift the same, means for applying the pressure of said conduit means atthe low pressure side of said port to one side of said movable wallurging the latter in opposition to said spring, and means connecting theother side of said well with the pressure of said induction conduit toadjust said seat to augment operation of said metering means tending toincrease the fuel flow to said engine during acceleration.

11. In a fuel system for an internal combustion engine having an airinduction conduit, fuel conduit means for supplying said engine withfuel, fuel metering means for regulating the fuel flow in said conduitmeans to said engine, said fuel metering means including a fuel chamberin said conduit means having a port, an adjustable valve seat at saidport, a shiftable valve element cooperable with said seat to regulatethe fuel flow through said port, a movable partition separating saidchamber into two parts with said port being in one thereof, saidpartition being shiftable in response to changes in the fuel pres suredifferential at its opposite sides and being operatively connected withsaid valve element to shift the same, valve actuating means responsiveto an operating condition of said engine and being cooperable with saidvalve element for shifting the same, and means responsive to pressurechanges in said induction conduit for adjusting said valve seat.

12. In a fuel system for an internal combustion engine having an airinduction conduit, fuel conduit means for supplying said engine withfuel, fuel metering means for regulating the fuel flow in said conduitmeans to said engine, said fuel metering means including a fuel chamberin said conduit means having a port, an adjustable valve seat at saidport, a shiftable valve element cooperable with said seat to regulatethe fuel flow through said port, a movable partition separating saidchamber into two parts with said port being in one thereof, saidpartition being shiftable in response to changes in the fuel pressuredifferential at its opposite sides and being operatively connected withsaid valve element to shift the same, valve actuating means responsiveto an operating condition of said engine and being cooperable with saidvalve element for shifting the same, and means responsive to pressurechanges in said induction conduit during acceleration of said engine foradjusting said seat to augment operation of said metering means tendingto increase the fuel flow to said engine.

13. In a fuel system for an internal combustion engine having an airinduction conduit and a throttle valve in said induction conduit, fuelconduit means for supplying said engine with fuel, fuel metering meanfor regulating the fuel flow in said conduit means to said engine, saidfuel metering means including a fuel chamber in said conduit meanshaving a port, an adjustable valve seat at said port, a shiftable valveelement cooperable with said seat to regulate the fuel flow through saidport, a movable partition separating said chamber into two parts withsaid port being in one thereof, said partition being shiftable inresponse to changes in the fuel pressure differential at its oppositesides and being operatively connected with said valve element to shiftthe same, valve actuating means responsive to an operating condition ofsaid engine and being cooperable with said valve element for shiftingthe same, and means responsive to the pressure increase in saidinduction conduit downstream of said throttle valve sesame 11 duringacceleration of said engine for adjusting said seat to. augmentoperation of said metering means tending to increase the fuel flow tosaid engine.

14. In a fuel system for an internal combustion engine having an airinduction conduit, fuel conduit means for supplying said engine withfuel, fuel metering means for regulating the fuel flow in said conduitmeans to said engine, said fuel metering means including a fuel chamherin said conduit means having a port, an adjustable valve seat at saidport, a shiftable valve element cooperable with said seat to regulatethe fuel flow through said port, a movable partition separating saidchamber into two parts with said port being in one thereof, saidpartition being shiftable in response to changes in the fuel pressuredifferential at its opposite sides and being operatively connected withsaid valve element to shift the same, valve actuating means responsiveto an operating condition of said engine and being cooperable with saidvalve element for shifting the same, resilient means yieldingly urgingsaid seat to a predetermined position of adjustment, and meansresponsive to pressure change in said in duction conduit duringacceleration of said enginefor adjusting said seat against the force ofsaid resilient means to. augment operation of said metering meanstending to increase the fuel flow to said engine.

15. In a fuel system for an internal combustion engine having an airinduction conduit, fuel conduit means for supplying said engine withfuel, fuel metering means for regulating the fuel .flow in said conduitmeans to said engine, said fuel metering means including a fuel chambetin said conduit means having a port, an adjustable valve seat at saidport, a shiftable valve element cooperable with said seat to regulatethe fuel flow through said port, a movable partition separating saidchamber into two parts with said port being in one thereof, saidpartition being shiftable. in response to changes in the fuel pressuredifferential at its Opposite sides and being operatively connected withsaid valve element to shift the same, valve actuating means responsiveto an operating condition of said engine and being cooperable with saidvalve element for shifting the same, and means responsive to pressurechanges in said induction conduit during acceleration of said engine foradjusting said seat to augment operation of s'aidmetering means tendingto increase the fuel flow to said engine, said last named meanscomprising a pressure chamber, a movable wall partitioning said pressurechamber into two parts and being operably connected with said seat, saidpressure chamber at one side of said movable wall being in communicationwith said induction conduit and being responsive to pressure changestherein, and a bleed duct connecting the parts of said pressurechamberat opposite sides of said wall for gradually equalizing the pressure atsaid opposite sides.

No references cited.

